Answer: 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here iron is having an oxidation state of +3 called as 
cation and oxide 
is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Answer:
30 hot dogs
Explanation:
It is given that :
There are 4 packets of eight wieners, i.e. 4 x 8 = 32 wieners
There are 3 bags of ten buns, i.e. 3 x 10 = 30 buns
One hot dogs need 1 bun and 1 wiener to make a hot dog.
There are 30 buns, so 30 hot dogs can be made out by using all the 30 buns and the 30 wieners out of the 32 wieners.
Therefore, 30 hot dogs.
And the number of extra wieners left = 32 - 30 = 2 wieners.
To answer this lets first see how much 1 kg is equal to in cg.
1 kg = 100000 cg
Now lets multiply:-
100000 × 1.7 = <span>170000
</span>
So, 1.7 kg = <span>170000 cg
</span>
Hope I helped ya!!!
Answer:
B) K⁺, Sr²⁺ , O²⁻
Explanation:
Potassium is present in group one. It is alkali metal and have one valance electron.Potassium need to lose its one valance electron and form cation to get complete octet.
That's why it shows K⁺.
Sr is alkaline earth metal. It is present in group two. It has two valance electrons. Strontium needed to lose its two valance electrons and get stable electronic configuration.
When it loses its two valance electrons it shows cation with charge of +2.
Sr²⁺
Oxygen is present in group 16. It has sex valance electrons. It needed two more electrons to complete the octet. That's why oxygen gain two electron and form anion with a charge of -2.
O²⁻
The melting point of the solid form of water, which is ice, is 0°C. When we convert both temperatures to kelvin by adding 273 to each we get the melting point of copper as 1357K and that of ice is 273K. Then, dividing the melting point of copper by the melting point of ice, both in absolute temperature scale. The answer would be 4.97. Thus, the energy of molecules of copper is approximately {five} times compared to that of water
